Note: The list of churches present in countries is still in development.

The British isles were Christianized as early as the second century. Since the Reformation, the Anglicans form the established church in England, and the Presbyterians the national church in Scotland. Along with the Methodists, Reformed and Baptists, many Free churches exist, and in the 20th century many other Pentecostal, Charismatic and Evangelical churches and groups have emerged. The independent African and Afro-Caribbean churches are very lively and strong. Among the Orthodox churches the Ecumenical Patriarchate is the largest. There are also sizeable Russian, Bulgarian, Armenian and other Orthodox churches. There are national councils of churches in England, Scotland, Wales and Ireland, and an overarching one for Britain and Ireland. All have the Catholic Church as member, except for Ireland. The Free churches have their own groupings. There is also an Evangelical Alliance, affiliated with the WEA.